A Answers (2)
Stacy Wiegman, PharmD, Pharmacy, answeredIf you have any sort of heart condition, be sure to check with your doctor before you take St. John's wort. Although people sometimes take St. John's wort to treat heart palpitations, there is not enough evidence yet to know whether it's effective. But it's well known that the herb can interact dangerously with a large number of drugs, including several that people take to treat heart conditions, such as digoxin (Lanoxin), warfarin (Coumadin), clopidogrel (Plavix) and some channel blockers.
Pina LoGiudice, Naturopathic Medicine, answeredKnown for its ability to stave off depression, it is not well known that the psychiatric-geared St. John's wort (Latin name Hypericum perforatum) may be gaining ground in the field of cardiology. It has shown itself to work well to beat depression in heart patients with less negative side effects on the heart. It also helps Plavix work in patients who did not do well on Plavix alone.
For patients with pre-existing conductive heart dysfunction or elderly patients, high-dose hypericum extract has been found to be safer with regard to cardiac function than tricyclic antidepressants (such as Elavil, Imipramine, and Amitrpytiline). Some researchers are thinking that St. John's wort may be indicated as a first line therapy for cardiac patients with depression.
Two new studies also suggest it may help patients lower the dose of platelet inhibitor Plavix, and help it work in the 20% of patients for whom it would normally not work. A study using the platelet inhibitor clopidogrel found that 2 out of 10 patients using clopidogrel are poor responders, but in these patients 300 mg of hypericum for two weeks found an increase of platelet inhibition of 20%. A previous study using 300 mg three times a day (t.i.d.) had an increase of 36%. Furthermore, no negative change was seen in patients on statin medications. Hypericum may be a good choice in poor responders, or to help lower the dose necessary in normal responders who are having side effects.